Steering column support structure

ABSTRACT

Apparatus for supporting a steering column of an automotive vehicle includes support structure have laterally spaced support flanges. A bracket on the steering column has bracket flanges. Insolator pads secured to the support flanges have a connection with the bracket flanges which releases in response to collapse of the steering column in a frontal impact. The support flanges have forward extensions providing ramps which engage the bracket flanges to prevent the steering column from rising during its collapse or during column stroke.

FIELD OF THE INVENTION

This invention relates generally to steering columns for automotivevehicles and more particularly to apparatus for preventing the rise ofthe steering column when it collapses in response to a frontal impact.

BACKGROUND AND SUMMARY

When a vehicle is involved in a frontal impact, the force of the driveragainst the steering wheel will, if the impact is severe enough, cause alongitudinal collapse of the steering column. At the same time, thesteering column tends to rise. In other words, the steering column whichnormally is inclined upwardly and rearwardly at a predetermined angle,will rise to a greater angle upon frontal impact. This is caused by theforward component of the driver force against the steering wheel inaddition to vehicle crush.

The rise in the steering column places the steering wheel/airbagassembly in an unfavorable position with respect to the driver's chest.When the driver's chest comes in contact with the steering wheel/airbagassembly, the force against this assembly has a considerable off-axisbending component which is increased due to the rise in the steeringcolumn. If the rise in the steering column is such that the off-axiscomponent of force on the steering wheel/airbag assembly acts above thecenter of mass of the driver's chest, then the driver tends to submarineor dive under the steering wheel, creating an even less favorablesituation.

In accordance with the present invention, the collapse of the steeringcolumn upon frontal impact is controlled so that there is no appreciableupward rise or tilt. More particularly, support structure is provided onthe vehicle frame preferably comprising support flanges which areopposed by flanges on a bracket carried by the steering column.Preferably, the support and bracket flanges are connected together byisolator pads. The isolator pads have a releasable or slidableconnection with the bracket flanges to permit the bracket flanges, andhence the steering column, to collapse, that is, move longitudinally, inthe event of a frontal impact. To prevent the steering column fromrising, ramps are provided which follow the column angle, and extendforwardly of the flanges on the support structure and guide the steeringcolumn as it collapses. The structure manages the energy of the driveron the wheel which would otherwise initiate column rise.

One object of this invention is to provide apparatus for supporting asteering column and controlling its collapse in a frontal impact withoutpermitting significant upward tilt of the steering column, having theforegoing features and capabilities.

Another object is to provide apparatus of the type described which iscomposed of a relatively few simple parts, is rugged and durable in use,and can be inexpensively manufactured and assembled, being particularlyeffective in preventing the rise of the steering column in the eventthat it collapses upon frontal impact.

These and other objects, features and advantages of the invention willbecome more apparent as the following description proceeds, especiallywhen considered with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a portion of a steering columnsupported by vehicle support structure, all constructed in accordancewith the present invention.

FIG. 2 is an exploded perspective view of the structure shown in FIG. 1.

FIG. 3 is a perspective view of part of the vehicle support structurefor the steering column.

FIG. 4 is a perspective view of the structure shown in FIG. 3, but seenfrom a different angle.

FIG. 5 is a detail perspective view, with parts broken away, showing thesteering column bracket and associated insulator pads.

FIG. 6 is a fragmentary side elevational view, with parts broken awayand in section, showing the steering column and support structuretherefor.

FIG. 7 is a view similar to FIG. 6, but showing the relationship of thesteering column to the support structure after collapse of the steeringcolumn following a frontal impact.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The elongated steering column 10 is shown in FIG. 1 at its normalorientation in which it extends longitudinally of the vehicle and isinclined upwardly and rearwardly, with a steering wheel 12 at its upperor rearward end.

To retain the steering column in the FIG. 1 position, support structureis provided including a support plate 14 which is rigidly secured to theframe of the vehicle. The support plate 14 has a pair of integral,laterally spaced-apart, parallel flanges 16 and 18 which are disposed onopposite sides of the steering column 10 and lie in a common plane aboveand parallel to the longitudinal axis of the steering column. A centersection 19 of the plate 14 reinforces the plate and integrally connectsthe flanges 16 and 18.

A bracket 20 is provided for the steering column 10. The bracket 20extends transversely of the steering column and has a generally U-shapedcentral portion 22 which loops under the steering column and is rigidlysecured thereto as by welding. The upper ends of the central portion 22are turned laterally outwardly to form integral, laterally spaced-apart,parallel bracket flanges 30 and 32. The bracket flanges are disposed onopposite sides of the steering column and lie in a common plane parallelto the plane of the support flanges 16 and 18. The bracket flanges 30and 32 are opposed to and located directly beneath the support flanges16 and 18. The bracket flanges 30 and 32 have longitudinally extendingslots 34 and 36 which are open at the rear edges of the flanges andclosed at the front edges thereof.

Isolator pads or capsules 40 and 42 are provided to dampen vibration.These isolator pads are made of any suitable sound and vibrationdampening material and may be made of a suitable plastic such as nylon.The isolator pads or capsules are generally square and flat, havinggrooves 50 and 52 in the opposite side edges which receive the materialof the bracket flanges 30 and 32 on opposite sides of the slots 34 and36 therein. This is a frictional, slidable connection between theisolator pads 40, 42 and the bracket flanges 30, 32 for a purpose to bedescribed.

The isolator pads are fastened to the coplanar flat bottom surfaces 54and 55 of support flanges 16 and 18 by bolts 56 and nuts 58. The headsof the bolts are rigidly secured to the support flanges 16 and 18 andthe shanks of the bolts extend downwardly through holes 59 in the centerof the isolator pads. The nuts 58 are threaded on the lower ends of thebolt shanks to securely fasten the isolator pads to the support flanges16 and 18.

The support structure for the steering column 10 also includes a strap60 on one side of the steering column and a similar strap (not shown) onthe opposite side. These straps have one end integrally connected to aplate 64 that is rigidly secured to a channel portion 66 of the vehicleframe. The opposite end of each strap is connected to the steeringcolumn at 68. The straps extend generally longitudinally of the steeringcolumn and are sufficiently flexible to yield when the steering columncollapses longitudinally. The straps aid in the support of the steeringcolumn during normal operating conditions, but are designed to bend andpermit the collapse of the steering column in a frontal impact. Thestraps are connected to the steering column at a point spaced forwardlyof the bracket 20.

It was stated previously that the connection between the isolator pads40 and 42 and the bracket flanges 30 and 32 is a slidable connection,and this is for the purpose of permitting the bracket 20 and hence thesteering column 10 to move or collapse longitudinally in a forwarddirection upon frontal impact, with the isolator pads remaining attachedto the support flanges 18 and 20 and sliding out of the slots 34 and 36as the bracket flanges move forward.

Also, as previously mentioned, there is a tendency for the steeringcolumn to tilt up as it collapses, and to prevent this from occurring,the support plate 14 has a pair of ramps 70 and 72 which extendforwardly from and in the same plane as the support flanges 16 and 18 inthe general direction of length of the steering column. The flat bottomsurfaces 74 and 76 of the ramps 70 and 72 extend in continuation of theflat bottom surfaces 54 and 55 of the support flanges 16 and 18 as seenin FIGS. 3, 4, 6 and 7 so that these ramp surfaces lie in the same planeas the bottom surfaces of the support flanges and provide a guide forthe steering column as it collapses.

As shown in FIG. 7, after the initial collapse of the steering columnand separation of the bracket flanges 30 and 32 from the isolator pads40 and 42, the bracket flanges are guided by these ramp surfaces 74 and76 and thus the steering column 10 is prevented from tilting upwardly.While there may be some slight fractional upward movement, depending onthe thickness of the isolator pads, this is so minimal that for allintents and purposes, there is virtually no upward tilt of the steeringcolumn as it collapses due to the sliding engagement of the bracketflanges 30 and 32 with the ramp surfaces 74 and 76. The ramps and hencethe ramp surfaces are long enough to provide a barrier to upward tiltthroughout the full stroke of the steering column as it collapses. Thelength of the extended ramp surfaces may, for example, be as much as 4inches to provide control over the entire steering column stroke.

Thus, the ramps 70 and 72 constitute a cantilevered forward surface ofthe support flanges 16 and 18 and during a vehicle crash, as thesteering column is released from its capsules, the bracket flanges ridealong these ramp surfaces. The end result is a "no-rise" steering columndesign that allows the steering column to stroke or collapse duringvehicle impact without any rise or upward tilt.

What is claimed is:
 1. Apparatus for supporting an elongated steeringcolumn of an automotive vehicle comprisinga vehicle frame, supportstructure secured to the vehicle frame having laterally spaced, firstand second support flanges, a bracket secured to the steering columnhaving laterally spaced, first and second bracket flanges extendinglaterally outwardly from opposite sides of said steering column beneathand opposed to said respective support flanges, means connecting saidfirst bracket flange to said first support flange and said secondbracket flange to said second support flange, said connecting meanscomprising a first isolator pad secured to said first support flange anda second isolator pad secured to said second support flange, said firstand second isolator pads frictionally engaging said first and secondbracket flanges to provide support for the steering column but beingreleaseable in response to forward movement of said bracket flanges andsteering column in the event of a longitudinal forward collapse of thesteering column in a frontal impact, and ramp means for guiding theforward collapse of the steering column in a frontal impact withoutpermitting significant upward tilt of the steering column, said rampmeans comprising ramps integral with and extending forwardly of saidrespective support flanges, and said bracket flanges being adapted toslide on said ramps to guide the forward collapse of the steeringcolumn.
 2. Apparatus as defined in claim 1, wherein said support flangeshave coplanar support surfaces to which said respective isolator padsare secured, and said ramps have ramp surfaces slidably contacted bysaid bracket flanges during the collapse of the steering column, saidramp surfaces being coplanar continuations of said support surfaces ofsaid support flanges.